Field of the Disclosure
The present disclosure, for example, relates to wireless communication systems, and more particularly to management of hybrid automatic repeat request (HARQ) feedback operations.
Description of Related Art
Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, and orthogonal frequency-division multiple access (OFDMA) systems (e.g., a Long Term Evolution (LTE) system).
By way of example, a wireless multiple-access communication system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, otherwise known as user equipments (UEs). A base station may communicate with UEs on downlink (DL) channels (e.g., for transmissions from a base station to a UE) and uplink (UL) channels (e.g., for transmissions from a UE to a base station).
Communications between base stations and UEs may include the use of various feedback signaling. One form of feedback is HARQ feedback. HARQ feedback may be provided by a receiving device to a sending device, and may include the transmission of various reporting signals to the sending device. Example reporting signals may include acknowledgement (ACK) signals representing an ACK state, and negative acknowledgement (NAK) signals representing a NAK state. A UE may also be in a discontinuous transmission (DTX) state. An ACK signal may be transmitted as part of HARQ feedback in response to successful reception and decoding of a data transmission. A NAK signal may be transmitted as part of HARQ feedback in response to a reception of a data transmission but an unsuccessful decoding of the data transmission. The UE may enter a DTX state when the UE fails to receive a data transmission.
In certain circumstances, however, such as when the communication time slots on which HARQ feedback is to be reported have been reduced in time to a duration of a single symbol (as may be the case in ultra low latency (ULL) environments), timely reporting of HARQ feedback may be a challenge.